Tissue expanders having integrated drainage and moveable barrier membranes

ABSTRACT

A tissue expander having an integrated drain includes a shell having an opening and one or more drainage holes, and an injection port disposed in the opening of the shell and forming a fluid-tight seal with the shell. The injection port includes a needle guard having a needle guard base with a top surface. The injection port includes a moveable barrier membrane overlying the top surface of the needle guard base. The moveable barrier membrane is moveable between a first position for inflating and deflating the shell with a first fluid and a second position for draining a second fluid from outside the shell. A magnet is coupled with the moveable barrier membrane, and a compressible spring is connected with the magnet. The compressible spring is compressed for storing energy as the moveable barrier membrane moves from the first position to the second position.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present patent application claims benefit of U.S. Provisional Application Ser. No. 62/752,839, filed Oct. 30, 2018, and is related to U.S. Provisional Application Ser. No. 62/752,813, filed Oct. 30, 2019, the disclosures of which are hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present patent application is generally related to implantable devices, and is more specifically related to tissue expanders having integrated drainage and fluid delivery components.

Description of the Related Art

Tissue expanders are devices that are implanted beneath the skin or muscle and then gradually inflated to stretch the overlying tissue. Expanders are commonly used to either create a pocket for receiving a permanent prosthesis, or to generate an increased skin surface area in anticipation of the new skin being utilized for grafting or reconstruction.

Tissue expanders are typically formed of a silicone polymer shell. After implantation, a fluid, such as saline, is periodically injected into the tissue expander to enlarge it over time. Between injections, the surrounding skin is permitted to stretch and grow to create the increased skin surface and the increased tissue pocket for receipt of a permanent implant. Typically, a tissue expander has an injection element through which fluid can be introduced into or withdrawn from the expander. One such injection element is an integrated port having a septum that can be pierced with a hypodermic needle for the introduction into or withdrawal of fluid from the expander. Alternatively, the injection element may be a self-sealing area on the tissue expander which allows penetration by a hypodermic needle and self-closing after the needle has been withdrawn from the expander.

Conventional, commercially available tissue expanders have a single port that is used for inflating and deflating the shell of the tissue expander. They have no means for draining fluid (e.g., seroma) that forms around the outside of the shell of the tissue expander after implantation.

After surgery, patients typically have surgical drains placed to prevent blood and lymphatic fluid from building up under the skin, allowing for a quicker recovery. Some patients are sent home with drains that are implanted and connected to an external reservoir. Emptying these reservoirs can be traumatic because the patients have to measure and empty the reservoirs periodically (e.g., every morning). Many patients loathe surgical drains and look forward to having the drains removed.

In view of the above-noted problems, there is a need for tissue expanders having a single injection port that may be used for both inflating and deflating the tissue expander and draining fluid that collects around the tissue expander following surgery. There is also a need for tissue expanders having a single injection port that may be used for inflation/deflation, draining fluid and infusing fluid (e.g., an antibiotic solution) around the outside of an implanted tissue expander. Moreover, there remains a need for tissue expanders that remove seroma fluid without the need for a drain being attached 24 hours a day to a patient.

SUMMARY OF THE INVENTION

In one embodiment, a tissue expander preferably has a single injection port that may be used for inflating and deflating the tissue expander and draining fluid that forms around the outside of the tissue expander after implantation. Having a single injection port allows the empty tissue expander to be more easily folded and have a lower profile, which reduces the incision size needed for implantation. In addition, having a single injection port desirably reduces the total metal content of the tissue expander, which helps with MRI visualization and patient radiation. In addition, having only one injection port (with less metal than found in tissue expanders having two injection ports) will reduce the overall weight of the tissue expander.

In one embodiment, the injection port desirably includes a needle guard having a needle guard base and a needle guard rim that projects upwardly from the needle guard base. In one embodiment, the needle guard may be made of metal. In one embodiment, the needle guard may be made of polymer materials such as plastic. The injection port preferably includes a barrier membrane that is positioned in the needle guard. The barrier membrane divides the injection port into two distinct chambers, an inflation chamber in fluid communication with one or more inflation/deflation ports that are used for inflating and deflating the tissue expander, and a drainage chamber in fluid communication with one or more drainage ports that are used for draining fluid that collects outside the tissue expander.

In one embodiment, the shape, size and configuration of the barrier membrane of the injection port creates a space without occluding the inflation/deflation ports of the tissue barrier. The drainage chamber is coupled with the drainage ports and at least one drainage conduit (e.g., tubing) that connects to at least one drainage hole formed in the outer shell of the tissue expander. In one embodiment, the drainage conduit desirably includes a one-way check valve (e.g., a duck bill valve). In one embodiment, the one-way check valve allows fluid (e.g., seroma) to be drawn from the tissue surrounding the tissue expander without the possibility of inadvertently delivering saline into the patient.

In one embodiment, a first, conventional injection needle may be used for inflating and deflating the tissue expander with a fluid (e.g., a saline solution). In one embodiment, the first needle is the standard, injection needle that is used for inflation and deflation of the tissue expander. In one embodiment, the first needle may be used for injecting a solution (e.g., saline solution) into an outer shell to expand the size of the tissue expander. The first needle may also be used for removing the solution from the outer shell for reducing the size of the tissue expander.

In one embodiment, a second, specially designed needle, referred to as a drainage needle, may be used for draining fluid (e.g., seroma) that collects around the outer shell of the tissue expander following implantation. In one embodiment, the second drainage needle is used for drainage purposes only. The drainage needle desirably includes a hollow, cylindrical shaft made of medical grade material (e.g., stainless steel). In one embodiment, the distal end of the hollow, cylindrical shaft is closed and has a sharpened tip. The drainage needle preferably includes a side port formed in the side of the hollow needle shaft that is proximally spaced from the sharpened tip. The side port desirably enables fluid such as seroma fluid to be drawn into the drainage needle. The distance between the side port opening and the sharpened distal tip preferably positions the side port in communication with a drainage chamber as described in more detail herein.

In one embodiment, a tissue expander preferably includes integrated drainage and infusion systems. In one embodiment, the tissue expander desirably has a single injection port that may be used for inflating and deflating the tissue expander, for draining fluid that builds up around the tissue expander following surgery and implantation, and for delivering fluids around the outside of the shell following implantation.

In one embodiment, a tissue expander having an integrated drain preferably includes a shell having an opening and one or more drainage holes, and an injection port disposed in the opening of the shell and forming a fluid-tight seal with the shell, the injection port including a needle barrier having a needle barrier base with a top surface. In one embodiment, the injection port preferably includes a moveable barrier membrane overlying the top surface of the needle barrier base. In one embodiment, the moveable barrier membrane is moveable between a first position for inflating and deflating the shell with a first fluid and a second position for draining a second fluid from outside the shell.

In one embodiment, the moveable barrier membrane is constructed from a rigid material such as a hard plastic or an elastomer. In one embodiment, the moveable barrier membrane has a hardness scale rating of Shore D 0-80.

In one embodiment, a magnet is coupled with the moveable barrier membrane. In one embodiment, a compressible spring is connected with the magnet. In one embodiment, the compressible spring is compressed for storing energy as the moveable barrier membrane moves from the first position to the second position. The energy may be released for returning the membrane to the first position.

In one embodiment, a needle may overlie the injection port and a second magnet may be coupled with the needle. In one embodiment, the second magnet repels the first magnet that is coupled with the moveable barrier for moving the moveable barrier from the first position to the second position.

In one embodiment, the tissue expander preferably includes an inflation port for inflating the shell with the first fluid, and a drainage port for draining the second fluid from outside the shell. In one embodiment, the inflation port is open and the drainage port is closed when the moveable barrier membrane is in the first position. In one embodiment, the inflation port is closed and the drainage port is open when the moveable barrier membrane is in the second position.

In one embodiment, a tissue expander preferably includes an injection port having a moveable barrier membrane that divides the injection port into an inflation chamber for inflating and deflating the tissue expander, and a drainage chamber for removing fluid that tends to collect around implants following surgery. In one embodiment, the moveable barrier membrane is connected to a magnet that, in turn, is coupled with a compressible spring. The barrier membrane is moveable between a first extended position in which the connected spring is extended, and a second retracted position in which the spring is compressed for storing energy in the spring.

In one embodiment, a first syringe with a needle is used for inflating and deflating the tissue expander. In one embodiment, a second syringe with a second needle contains a reversed pole magnet to repel the magnet coupled with the moveable membrane to occlude various openings. In the extended position, the moveable barrier membrane occludes a drainage port, with the compression spring keeping the moveable barrier membrane in place (i.e., in the extended position). With the barrier membrane in the extended position, saline injection for inflation and deflation is accomplished. A magnet mounted on the second syringe will repel the magnet coupled with the barrier membrane to push the movable barrier membrane down allowing drainage via syringe suction.

In one embodiment, a tissue expander having an integrated drain preferably includes a shell having an opening and one or more drainage holes, and an injection port disposed in the opening of the shell and forming a fluid-tight seal with the shell. In one embodiment, the injection port may include a needle barrier having a needle barrier base with a top surface, and a barrier membrane overlying the top surface of the needle barrier base. In one embodiment, the barrier membrane defines an inflation chamber located between the top surface of the needle guard base and a bottom surface of the barrier membrane, and a drainage chamber overlying a top surface of the barrier membrane. In one embodiment, one or more inflation ports are in fluid communication with the inflation chamber for inflating and deflating the shell with a first fluid. In one embodiment, a drainage conduit is in fluid communication with and extends between the drainage chamber and the one or more drainage holes for draining a second fluid from outside the shell.

In one embodiment, a first needle is used for inflating the shell and a second needle is used for draining fluid from around the outside of the shell. In one embodiment, the first needle has an opening at a pointed distal tip. In one embodiment, the first needle is adapted for insertion into the injection port so that the opening at the pointed distal tip is aligned with the inflation chamber for selectively inflating and deflating the shell using the first fluid. In one embodiment, the second needle has a closed distal tip and a side port spaced proximally from the closed distal tip. The second needle is adapted from insertion into the injection port so that the side port of the second needle is aligned with the drainage chamber for draining the second fluid from outside the shell.

In one embodiment, a tissue expander may include an infusion chamber overlying the top surface of the barrier membrane and separated from the drainage chamber, and an infusion conduit in fluid communication with and extending between the infusion chamber and at least one of the drainage holes for delivering an infusion fluid to the outside the shell.

Dip molding using an appropriately sized and shaped mandrel can be used to form the outer shell, although other suitable means such as injection molding or spraying may also be used. With dip molding, the mandrel is dipped into silicone dispersion and then removed to allow for partial cure and solvent evaporation. The process is generally repeated several times. Once the outer shell has been formed it is removed from the mandrel. The dip molding process results in the formation of a partial shell that has an opening, e.g., a circular hole (patch hole), on the posterior side. The injection port is installed and the patch hole is subsequently covered with a patch that seals the hole, thus forming a complete, fluid impervious shell. The patch may be attached to the partial shell using silicone rubber or other similar biocompatible adhesive. The completed shell can either be non-filled or partially prefilled. After implantation, the expander is intraoperatively filled through the injection port with saline, gel, foam, or combinations of these materials or other suitable materials known in the art to gradually expand the tissue expander to the desired dimensions. Filling through the injection port typically takes place over the course of multiple office visits.

In one embodiment, a tissue expander having an integrated drain preferably includes a shell having an injection port opening and one or more drainage holes, and an injection port disposed in the injection port opening of the shell, whereby the injection port forms a fluid-tight seal with the shell.

In one embodiment, the injection port desirably includes a needle guard having a needle guard base with a top surface. In one embodiment, the injection port preferably has a moveable barrier membrane overlying the top surface of the needle guard base. In one embodiment, the moveable barrier membrane is moveable between a first position for inflating and deflating the shell with a first fluid and a second position for draining a second fluid from outside the shell.

In one embodiment, the needle guard includes a needle guard rim that extends upwardly from the needle guard base. In one embodiment, the needle guard rim surrounds an outer perimeter of the moveable barrier membrane.

In one embodiment, the injection port preferably includes one or more inflation ports that are formed in the needle guard rim, which are configured for directing the first fluid into the shell for inflating the shell and removing the first fluid from the shell for deflating the shell.

In one embodiment, the injection port preferably includes at least one drainage port formed in the needle guard rim that is in fluid communication with the one or more drainage holes of the shell for drawing the second fluid from outside the shell via the one or more drainage holes.

In one embodiment, the moveable barrier membrane may have a membrane rim at an outer perimeter of the moveable barrier membrane. In one embodiment, when the moveable barrier membrane is in the first position, the membrane rim closes the at least one drainage port and opens the one or more inflation ports, and when the moveable barrier membrane is in the second position the membrane rim opens the at least one drainage port and closes the one or more inflation ports.

In one embodiment, the needle guard base extends along a first axis and the needle guard rim extends along a second axis that is perpendicular to the first axis of the needle guard base. In one embodiment, as the moveable barrier membrane moves between the first and second positions, the moveable barrier membrane including the membrane rim travel up and down relative to the needle guard base along the second axis, which is perpendicular to the first axis of the needle guard base.

In one embodiment, a tissue expander may include a drainage conduit having a first end in fluid communication with the at least one drainage port and a second end in fluid communication with the one or more drainage holes formed in the shell for draining the second fluid from outside the shell.

In one embodiment, the tissue expander may include a magnet coupled with the moveable barrier membrane, and a compressible spring connected with the magnet. In one embodiment, the compressible spring is compressible for storing energy as the moveable barrier membrane moves from the first position to the second position.

In one embodiment, the magnet has an upper end that is connected with an underside of the moveable barrier membrane and a lower end that is connected with the compressible spring.

In one embodiment, a needle may be inserted into the injection port for inflating the shell and/or draining fluid that collects around the outside of the shell.

In one embodiment, a second magnet is preferably coupled with the needle. In one embodiment, when the needle is inserted into the injection port, the second magnet desirably repels the first magnet coupled with the moveable barrier for moving the moveable barrier from the first position to the second position.

In one embodiment, a tissue expander having an integrated drain preferably includes a shell having an injection port opening and one or more drainage holes formed in the shell, and an injection port disposed in the injection port opening.

In one embodiment, the injection port preferably includes a needle guard having a needle guard base and a needle guard rim that extends upwardly from the needle guard base.

In one embodiment, the injection port preferably has one or more inflation ports formed in the needle guard rim that are in fluid communication with an interior region of the shell.

In one embodiment, the injection port preferably includes at least one drainage port formed in the needle guard rim that is in fluid communication with the one or more drainage holes formed in the shell.

In one embodiment, the tissue expander preferably includes a moveable barrier membrane overlying a top surface of the needle guard base and being surrounded by the needle guard rim. In one embodiment, the moveable barrier membrane is moveable between a first position for closing the at least one drainage port and opening the one or more inflation ports and a second position for opening the at least one drainage port and openings the one or more inflation ports.

In one embodiment, the moveable barrier membrane desirably has an outer perimeter and a membrane rim located at the outer perimeter of the moveable barrier membrane.

In one embodiment, the needle guard base extends along a first axis and the membrane rim of the moveable barrier membrane extends along a second axis that is perpendicular to the first axis of the needle guard base. In one embodiment, as the moveable barrier membrane moves between the first and second positions, the moveable barrier membrane including the membrane rim desirably travel up and down relative to the needle guard base along the second axis that is perpendicular to the first axis of the needle guard base.

In one embodiment, when the moveable barrier membrane is in the first position the membrane rim closes the at least one drainage port and opens the one or more inflation ports, and when the moveable barrier membrane is in the second position the membrane rim opens the at least one drainage port and closes the one or more inflation ports.

In one embodiment, the one or more inflation ports formed in the needle guard rim are configured for directing a first fluid into the shell for inflating the shell and removing the first fluid from the shell for deflating the shell, and the at least one drainage port formed in the needle guard rim is in fluid communication with the one or more drainage holes formed in the shell for drawing a second fluid from outside the shell.

In one embodiment, a magnet may be coupled with an underside of the moveable barrier membrane. In one embodiment, a compressible spring is desirably connected with the magnet, whereby the compressible spring is compressed for storing energy as the moveable barrier membrane moves from the first position to the second position.

In one embodiment, the magnet has an upper end that is connected with the underside of the moveable barrier membrane and a lower end that is connected with the compressible spring.

In one embodiment, the tissue expander may include a needle configured for being inserted into the injection port, and a second magnet coupled with the needle. In one embodiment, when the needle is inserted into the injection port the second magnet repels the first magnet coupled with the moveable barrier for moving the moveable barrier from the first position to the second position.

In one embodiment, a tissue expander having an integrated drain preferably includes a shell having an injection port opening and one or more drainage holes formed in the shell, and an injection port disposed in the injection port opening.

In one embodiment, the injection port preferably includes a needle guard having a needle guard base that extends along a first axis and a needle guard rim that extends upwardly from the needle guard base.

In one embodiment, the injection port preferably includes one or more inflation ports formed in the needle guard rim that are in fluid communication with an interior region of the shell for introducing a first fluid into the shell.

In one embodiment, the injection port preferably includes at least one drainage port formed in the needle guard rim that is in fluid communication with the one or more drainage holes formed in the shell for draining a second fluid from outside the shell via the one or more drainage holes.

In one embodiment, the tissue expander preferably includes a moveable barrier membrane overlying a top surface of the needle guard base and being surrounded by the needle guard rim. In one embodiment, the moveable barrier membrane is moveable along a second axis that is perpendicular to the first axis of the needle guard base for moving between a first position for closing the at least one drainage port and opening the one or more inflation ports and a second position for opening the at least one drainage port and closing the one or more inflation ports.

In one embodiment, a magnet may be coupled with the moveable barrier membrane, and a compressible spring is connected with the magnet. In one embodiment, the magnet is disposed between the moveable barrier membrane and the compressible spring.

In one embodiment, the tissue expander may include a needle configured for insertion into the injection port, and a second magnet coupled with the needle, whereby when the needle is inserted into the injection port the second magnet repels the first magnet coupled with the moveable barrier for moving the moveable barrier from the first position to the second position.

In one embodiment, the moveable barrier membrane preferably has an outer perimeter and a membrane rim located at the outer perimeter of the moveable barrier membrane that extends along the second axis that is perpendicular to the first axis of the needle guard base. In one embodiment, when the moveable barrier membrane is in the first position the membrane rim closes the at least one drainage port and opens the one or more inflation ports, and when the moveable barrier membrane is in the second position the membrane rim opens the at least one drainage port and closes the one or more inflation ports.

In one embodiment, the tissue expander desirably includes a drainage conduit having a first end in fluid communication with the at least one drainage port and a second end in fluid communication with the one or more drainage holes formed in the shell for draining the second fluid from outside the shell via the one or more drainage holes.

These and other preferred embodiments of the present invention will be described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a perspective view of a tissue expander having an integrated drainage system, in accordance with one embodiment of the present patent application.

FIG. 1B shows a side view of the tissue expander shown in FIG. 1A.

FIG. 2 shows a cross-sectional view of a tissue expander having an integrated drainage system, in accordance with one embodiment of the present patent application.

FIG. 3 shows a magnified view of an injection port of the tissue expander shown in FIG. 3.

FIG. 4A shows a partial cross-sectional side view of the tissue expander shown in FIGS. 1A and 1B.

FIG. 4B shows a partial cross-section top view of the tissue expander shown in FIGS. 1A and 1B.

FIG. 5A shows an inner face of a drainage manifold of an integrated drainage system of a tissue expander, in accordance with one embodiment of the present patent application.

FIG. 5B shows an outer face of the drainage manifold shown in FIG. 5A.

FIG. 6A shows a perspective view of a drain assembled with the drainage manifold of FIGS. 5A and 5B, in accordance with one embodiment of the present patent application.

FIG. 6B shows a cross-sectional view of the drain shown in FIG. 6A.

FIG. 7 shows a method of inflating a tissue expander, in accordance with one embodiment of the present patent application.

FIG. 8A shows a method of draining a tissue expander having an injection port and an integrated drainage system, in accordance with one embodiment of the present patent application.

FIG. 8B shows a magnified view of the injection port of the tissue expander shown in FIG. 8A.

FIG. 9 shows a cross-sectional view of a tissue expander having an integrated drain, in accordance with one embodiment of the present patent application.

FIG. 10A shows a partial cross-sectional view of a tissue expander having an integrated drainage and infusion system, in accordance with one embodiment of the present patent application.

FIG. 10B shows a side view of the tissue expander shown in FIG. 10A.

FIG. 10C shows a cross-sectional side view of the tissue expander shown in FIGS. 10A and 10B.

FIG. 11 shows a drainage conduit of the tissue expander shown in FIGS. 10A-10C, in accordance with one embodiment of the present patent application.

FIG. 12 shows an infusion conduit of the tissue expander shown in FIGS. 10A-10C, in accordance with one embodiment of the present patent application.

FIG. 13A shows an injection port of a tissue expander, the injection port having a moveable membrane that is coupled with a magnetic element, in accordance with one embodiment of the present patent application.

FIG. 13B shows another view of the injection port shown in FIG. 13A

FIG. 14A shows a first step of a method of using the injection port of FIGS. 13A and 13B for draining fluid from around the perimeter of a tissue expander, in accordance with one embodiment of the present patent application.

FIG. 14B shows a second step of a method of using the injection port of FIGS. 13A and 13B for draining fluid from around the perimeter of a tissue expander, in accordance with one embodiment of the present patent application.

FIG. 14C shows another view of the injection port of FIG. 14B.

FIG. 15A shows a top view of a tissue expander having an integrated drainage system including drainage holes provided on a top side of an outer shell, in accordance with one embodiment of the present patent application.

FIG. 15B shows a side perspective view of the tissue expander shown in FIG. 15A.

FIG. 16A shows a top perspective view of a tissue expander having an integrated drainage system including radially extending drainage holes, in accordance with one embodiment of the present patent application.

FIG. 16B shows a side view of the tissue expander shown in FIG. 16A.

FIG. 17 shows a schematic view of a tissue expander having an integrated drainage system, in accordance with one embodiment of the present patent application.

FIG. 18 shows a schematic view of a tissue expander having integrated systems for draining and infusing fluid, in accordance with one embodiment of the present patent application.

FIG. 19 shows a schematic view of a tissue expander having integrated, inflation, drainage and infusion systems, in accordance with one embodiment of the present patent application.

FIG. 20 shows a tissue expander having a first injection port for draining and infusing fluid, and a second ejection port for inflating the tissue expander with a solution, in accordance with one embodiment of the present patent application.

FIG. 21 shows systems for creating vacuum for draining fluids that collect around tissue expanders, in accordance with one embodiment of the present patent application.

FIG. 22A shows a perspective view of a drain that is adapted for assembly with the drainage manifold of FIGS. 5A and 5B, in accordance with one embodiment of the present patent application.

FIG. 22B shows a cross-sectional view of the drain shown in FIG. 22A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIGS. 1A and 1B, in one embodiment, a tissue expander 100 preferably includes a shell 102 and an injection port 104 located at a top side of the shell. The shell 102 may have any desired shape and any thickness that is suitable for the purpose of the particular tissue expander. The shell 100 may be formed of a biocompatible elastomer material such as silicone.

In one embodiment, the tissue expander 100 preferably includes one or more stability tabs 106 that may be used for securing the tissue expander 100 to tissue. In one embodiment, sutures or surgical fasteners may be utilized for securing the one or more stability tabs 106 to a patient's tissue. In one embodiment, the tissue expander 100 desirably includes one or more drainage holes 108 that are provided on the shell 102. The one or more drainage holes 108 may be used to drain fluid (e.g., seroma fluid) that may accumulate around the tissue expander 100 following surgical implantation.

Referring to FIGS. 2 and 3, in one embodiment, the injection port 104 may be secured to an opening that is present in the shell for sealing the shell 102. In one embodiment, the injection port 104 is fitted into the opening in the shell 102 at a location that faces toward a patient's skin surface. The injection port may be formed of an elastomeric material. In one embodiment, the injection port 104 desirably includes a septum region 110 that is preferably located at the central region of the upper surface of the injection port 104 and/or the tissue expander 100. The septum region 110 is desirably self-sealing for preventing the leaking of fluid from the tissue expander 100 after an injection needle is removed from the injection port 104.

In one embodiment, the injection port 104 desirably includes an outer flange 112 that overhangs the outer surface of the shell 102. In one embodiment, the injection port 104 desirably includes a self-sealing, safety patch 114 that is secured to the inner surface of the shell 102, whereby the shell is at least partially sandwiched between the flange 112 of the injection port and the self-sealing, safety patch 114. The self-sealing, safety patch preferably has a diameter that is larger than the flange 112 of the injection port 104 so that the safety patch extends beyond the outer perimeter of the flange 112.

In one embodiment, an appropriately sized and shaped mandrel may be used to form the shell 102 of the tissue expander 100. In one embodiment, the shell 102 may be formed using a dip molding methodology, although other methodologies may be used including spraying a mandrel with a shell forming solution or injection molding. During a dip molding method, a mandrel is dipped into silicone dispersion and then removed to allow for partial cure and solvent evaporation. The dipping step is repeated several times. Once the shell has been formed, it is removed from the mandrel. The dip molding process results in the formation of a partial shell that has an opening, e.g., a circular hole (patch hole). The injection port 104 and the safety patch 114 are installed, thus forming a complete, fluid impervious shell. The safety patch 114 may be attached to the inner surface of the shell 102 using silicone rubber or other similar biocompatible adhesives. The completed shell can be non-filled or partially pre-filled. After implantation, the tissue expander 100 is filled through the septum region 110 with saline, gel, foam, or combinations of these materials or other suitable materials known in the art to gradually expand the tissue expander 100 to the desired dimensions. This typically takes place over the course of multiple office visits.

In one embodiment, the injection port 104 desirably includes a needle guard 116 having needle guard base 118 and a needle guard rim 120 that extends upwardly from the needle guard base 118. In one embodiment, the needle guard rim 120 completely surrounds the outer perimeter of the needle guard base 118.

In one embodiment, the injection port 104 desirably includes a barrier membrane 122 that extends from one side of the needle guard rim 120 to an opposite side of the needle guard rim portion 120. In one embodiment, the barrier membrane 122 preferably overlies the needle guard base 118 and is co-extensive with the area of the needle guard base 118. The barrier member 122 preferably divides the injection port 104 into an inflation chamber 124 that is used to introduce an inflation solution into the shell 102 to expand the tissue expander and/or remove a solution from the shell to deflate the tissue expander, and a drainage chamber 126 that is used to drain fluid (e.g., seroma fluid) that may collect around the shell 102 of the tissue expander 100 following implantation.

In one embodiment, the inflation chamber 124 is in fluid communication with shell inflation ports 128A, 128B that pass through lateral openings provided in the needle guard rim 120. In one embodiment, an injection needle may be used to introduce fluid (e.g., saline solution) into the inflation chamber 124 whereupon it flows through the inflation ports 128A, 128B for inflating the shell 102 with the solution. In one embodiment, an injection needle may be used to generate a vacuum within the inflation chamber with removing fluid from the shell 102 to deflate the tissue expander 100.

In one embodiment, the drainage chamber 126 of the injection port 104 preferably includes a drainage port 130 that passes through an opening 132 formed in the needle guard rim 120 of the needle guard 116. In turn, the drainage port 130 is connected to a first end 134 of a drainage conduit 136. The drainage conduit 136 desirably has a second end 138 that is coupled with a drain 140, which is in fluid communication with one or more drainage holes 108 formed in the shell 102.

In one embodiment, a first needle 142 is utilized for inflating and deflating the shell 102 of the tissue expander 100. The first needle 142 preferably has a pointed tip 144 and an opening 146 provided at the pointed tip 144. In one embodiment, the pointed tip 144 of the first needle 142 is passed through the septum 110 and the barrier membrane 122 so that the opening 146 at the distal tip 144 of the first needle 142 is aligned with the inflation chamber 124 of the injection port 104. Once the opening 146 of the first needle 142 is positioned within the inflation chamber 124, a fluid (e.g., saline solution) may be passed through the needle opening 146 whereupon the injected fluid flows into the inflation chamber 124, through lateral openings in the needle guard rim 120, and through the inflation ports 128A, 128B for inflating the shell 52 with the injected fluid. In order to deflate the tissue expander 100, the first needle 142 may be used to remove fluid from the shell by withdrawing fluid through the inflation ports 128A, 128B and into the inflation chamber 124, whereupon the fluid may be removed from the shell 102 via the first needle 142.

In one embodiment, a second needle 148 may be used to drain fluid that collects around the outer perimeter of the tissue expander 100. In one embodiment, the second needle 148 has a pointed distal tip 150 and a side port 152 that is spaced proximally away from the pointed distal tip 150. As will be described in more detail herein, the side port 152 of the second needle enables fluid that has collected around the outside of the shell to be drained and removed from a patient's body.

Referring to FIGS. 4A and 4B, in one embodiment, the tissue expander 100 preferably includes a drainage manifold 154 that is aligned with and covers the one or more drainage holes 108 that are provided on the shell 102. In one embodiment, the second end 138 of the drainage conduit 136 is secured to a drainage manifold port 156 for connecting the drainage conduit 136 to the drainage manifold 154.

In one embodiment, the drainage conduit 136 desirably includes a one-way check valve 158 (FIG. 2) that enables the fluid passing through the drainage conduit to move in only one direction designated DIR1, i.e., toward the drainage chamber 126 (FIG. 3) of the injection port 104.

Referring to FIGS. 5A and 5B, in one embodiment, the drainage manifold 154 desirably includes the drainage manifold port 156 that projects from an inner face 158 of the drainage manifold 154. In one embodiment, the drainage manifold 154 preferably has an outer face 160 that surrounds a trough 162, which is adapted to receive one or more drains 140 (FIG. 2) that are preferably aligned with the one or more drainage holes 108 (FIG. 1A) provided on the shell. The drainage manifold port 156 is desirably in fluid communication with the trough 162 provided at the front face 160 of the drainage manifold 154. In one embodiment, the outer face 160 of the drainage manifold 154 is preferably secured to the inner surface of the shell 102 (FIG. 1A) to form a water-tight seal with the inner surface of the shell so as to divide the fluid that is used to inflate and deflate the shell from the fluid that is drained from outside the shell.

In one embodiment, one or more drains 140 (FIG. 2) are desirably positioned within the trough 162 of the drainage manifold 154 for draining fluid from around the perimeter of the tissue expander. In one embodiment, the drains are desirably aligned with the drainage holes 108 (FIG. 1A) formed in the shell 102 of the tissue expander 100.

Referring to FIGS. 6A and 6B, in one embodiment, a drain 140 preferably has a core 166 with struts 168 that project from the core 166 along the longitudinal axis of the core. Each of the outer ends of the struts 168 have respective overhang portions 170 which extend longitudinally throughout the length of the struts 168. As shown in FIG. 6B, in one embodiment, the overhang portions 170 are arcuate members that extend on either side of their respective struts 168. The overhang portions 170 are sized to form a generally oval shaped member at the periphery of the drain 140, with small gaps between the adjacent overhang portions 170. Each of these gaps forms a longitudinal groove 172, parallel to the longitudinal axis of the core 166, and extending throughout the length of the drain 140. The core portion 166, the struts 168, and the overhand portions 170 cooperate to form plural channels or lumens 174 that extend along the length of the drain 140. The longitudinal grooves 172 permit fluid communication between the respective lumens 174 and a wound.

In one embodiment, the drain 140 may be similar to the surgical drains disclosed in U.S. Pat. No. 4,398,910 to Blake et al., the disclosure of which is hereby incorporated by reference herein.

Referring to FIG. 7, in one embodiment, in order to inflate the tissue expander 100, the pointed distal tip 144 of the first needle 142 is passed through both the septum region 110 of the injection port 104 and the barrier membrane 122 until the opening 146 at the distal tip 144 of the inflation needle 142 is aligned with the inflation chamber 124 of the injection port. In one embodiment, a fluid (e.g., saline solution) is injected from the opening 146 at the distal tip 144 of the first needle 142 whereupon the injected fluid flows into the inflation chamber 124 and through the inflation ports 128A, 128B for inflating the shell 102 and expanding the tissue expander 100. The distal tip 144 is desirably halted by the needle guard base 118 of the needle guard 116 for preventing the distal tip of the first needle from passing through the bottom of the injection port 104 and/or damaging the shell of the tissue expander. If the opening 146 at the distal tip 144 of the first needle 142 were improperly aligned with the drainage chamber 126 of the injection port 104 and fluid under pressure is injected from the opening 146 of the first needle 142, the one-way check valve 158 (FIG. 2) provided inside the drainage conduit 136 will prevent the fluid from passing through the drainage conduit and reaching the drain 140 located at the second end 138 of the drainage conduit 136.

Referring to FIGS. 8A and 8B, in one embodiment, bodily fluid that collect around the shell 102 of the tissue expander 100 may be drained from the one or more drainage openings 108 (FIG. 1A) provided on the shell 102. In one embodiment, the second needle 148 (FIG. 3) is utilized for draining the fluid that has accumulated around the outer perimeter of the shell 102. In one embodiment, the pointed distal tip 150 of the second needle 148 is advanced through the barrier membrane 122 until the pointed tip 150 abuts against the top surface of the needle guard base 118 of the needle guard 116. When the pointed distal tip 150 of the second needle 148 engages the needle guard base 118, the side port 152 of the second needle 148 (which is spaced from the distal tip 150) is preferably aligned with the drainage chamber 126 of the injection port 104 that overlies the top surface of the barrier membrane 122. A vacuum may then be drawn through the second needle 148 for withdrawing fluid (e.g., seroma) through the drainage conduit 136. The drainage conduit 136 preferably includes the one-way check valve 158 that enables the accumulated fluid to flow in only one direction (e.g., toward the injection port 104). The drained fluid preferably passes through the one-way check valve 158, through the drainage port 130, and into the drainage chamber 126 where it is withdrawn through the side port 152 of the drainage needle 148. FIG. 8B shows the flow of the drained fluid as it flows through the one-way check valve 158, the first end 134 of the drainage conduit 136, the drainage chamber 126, and into the side port 152 of the second needle 148 for being removed from the shell 102 of the tissue expander 102.

Referring to FIG. 9, in one embodiment, a tissue expander 200 has an integral drain provided therein for draining fluid and/or liquids that accumulate around the perimeter of the shell 202 of the tissue expander. In one embodiment, the tissue expander 200 preferably includes a drainage conduit 236 having a first end 234 that is coupled with a drainage port 230 of an injection port 204, and a second end 238 that is coupled with a drainage manifold 254 that is positioned adjacent drainage openings 208 provided on the shell 202. In one embodiment, the integral drain does not include a drain 140 (FIG. 6A) similar to that shown and described above in FIGS. 6A and 6B. Rather, the integral drain includes a sealed drain cover 245 that is secured with an inner face 258 of the drainage manifold 254. The outer face 260 of the drainage manifold 254 is preferably secured to an inner surface 255 of the shell 202 to form a water-tight seal between the inner surface of the shell and the outer face of the drainage manifold 254 for separating the inflation fluid that circulates inside the shell 202 from the liquid that accumulates around the shell 202 and that is drained through the one or more drainage holes 208.

Referring to FIGS. 10A-10C, in one embodiment, a tissue expander 300 preferably includes an outer shell 302, an injection port 304, stabilizing tabs 306, and drainage and infusion holes 308 provided on the shell 302. In one embodiment, the tissue expander 300 desirably includes a manifold 354 that is preferably used for both drainage and infusion and that is positioned inside the shell 302 adjacent the drainage and infusion holes 308. In one embodiment, a drainage conduit 336A has a first end 334A coupled with a drainage and infusion chamber 326 of the injection port 304 and a second end 338A coupled with a drainage port 356A of the manifold 354. As will be described in more detail herein, the drainage conduit 336A desirably includes a one-way check valve 358A that allows fluid that is drained through the holes 308 to flow from the second end 338A to the first end 334A of the drainage conduit 336A, but not in the opposite direction from the first end 334A to the second end 338A of the drainage conduit 336A.

In one embodiment, the tissue expander 300 desirably includes an infusion conduit 336B having a first end 334B coupled with the drainage and infusion chamber 325 of the injection port 304 and a second end 338B coupled with an infusion port 356B provided on the manifold 354. In one embodiment, a solution (e.g., a medical solution, an antibiotic) may be passed through the infusion conduit 336B for being dispensed from the holes 308 formed in the shell 252. In one embodiment, the infusion conduit 336B desirably includes a one-way check valve 358B that allows an infusion solution to flow from the first end 334B of the infusion conduit 336B to the second end 338B of the infusion conduit 336B, but not flow through the infusion conduit 336B in the opposite direction.

Referring to FIGS. 10C and 11, in one embodiment, the tissue expander 300 desirably includes the drainage conduit 336A having a one-way check valve 358A that allows the drained fluid to flow from the second end 338A to the first end 334A of the drainage conduit 336A in the direction designed DIR1, but not in the reverse direction designed DIR2. In one embodiment, the manifold 354 is secured to the second end 338A of the drainage conduit 336A. The drainage system desirably includes one of more drains 340 that are located within the trough 362 of the manifold 354 and that are located between the opening at the second end 338A of the drainage conduit 336A and the one or more holes 308 formed in the shell 302. The fluid that is drained through the one or more holes 308 passes through the one or more drains 340 and into the drainage conduit 336A.

FIG. 12 shows the one-way check valve 358B provided in the infusion conduit 336B. The one-way check valve 358B enables the infusion fluid to flow in only one direction designed DIR2 from the first end 284B to the second end 288B of the infusion conduit 286B, but not in the opposite direction designated DIR1.

Referring to FIGS. 13A and 13B, in one embodiment, an injection port 404 of a tissue expander 400 desirably includes a moveable barrier membrane 422 that is positioned inside a needle guard 416 having needle guard base 418 and a needle guard rim 420 that projects upwardly from the needle guard base 418. The injection port 404 preferably includes a magnet 475 that is positioned atop a compressible spring 485 that normally urges the moveable barrier membrane 422 into an extended position shown in FIGS. 13A and 13B. In one embodiment, the moveable barrier membrane 422 desirably includes a membrane rim 425 that blocks a drainage port 430 when the moveable barrier membrane 422 is in the extended position shown in FIGS. 13A and 13B. In one embodiment, the magnet 475 and the movable barrier membrane 422 are connected together and move together between an extended position shown in FIGS. 13A and 13B and a compressed position shown in FIGS. 14B and 14C.

In one embodiment, the moveable barrier membrane 422 is constructed from a rigid material such as a hard plastic or an elastomer. In one embodiment, the moveable barrier membrane has a hardness scale rating of Shore D 0-80.

In one embodiment, in order to inflate a shell of a tissue expander with a solution, an inflation needle 442 having a distal tip 444 with an opening 446 is preferably passed through the dome 410 of the injection port 404 until the distal tip 444 of the needle 442 abuts against the moveable barrier membrane 422. The compression spring 485 is extended so that the magnet 475 and the moveable barrier membrane 422 are in the extended position. When a solution is injected from the opening 446 at the distal tip 444 of the needle 442, the injected solution desirably flows through openings 435 in a floor of the barrier membrane 422 and through an inflation port 428 for filling an outer shell of the tissue expander 400.

Referring to FIG. 14A, in one embodiment, a second magnet 495 may be positioned over the elongated shaft of the injection needle 442. The second magnet 495 may be positioned adjacent a lower end of a syringe. The second magnet 495 preferably generates a magnetic field that repels the first magnet 475 located inside the injection port 440. The repelling forces between the magnets 475, 495 move the movable barrier membrane 422 into the compressed position shown in FIG. 14A, whereupon the barrier rim 422 of the barrier membrane 422 is positioned below an opening of a drainage port 430 so that fluid accumulating around the perimeter of the tissue expander may be withdrawn through the drainage port. FIG. 14A shows a phantom line P that indicates a possible insertion path for the needle 442 when the needle is inserted into the injection port 404.

Referring to FIGS. 14B and 14C, the second magnet 495 (FIG. 14B) around the injection needle 442 repels the first magnet 475 within the injection port 404 for compressing the spring 485 (FIG. 14B) and moving the movable barrier membrane 422 into the compressed position. The peripheral rim 425 of the moveable barrier membrane 422 no longer blocks the drainage port 430 so that drainage fluid may be drawn into the opening 446 at the pointed tip 444 of the injection needle 442. As the moveable barrier membrane 422 moves into the lower, compressed position shown in FIGS. 14B and 14C, the compression spring 485 (FIG. 14B) coupled with an underside of the first magnet 475 is compressed. When the second magnet 495 (FIG. 14B) is moved away from the injection port 404, the energy stored in the compression spring 485 (FIG. 14B) will return the movable barrier membrane 422 back to the extended position shown in FIGS. 13A and 13B. When the movable barrier membrane 422 is returned to the extended position shown in FIGS. 13A and 13B, the peripheral rim 425 of the movable barrier membrane 422 once again blocks the drainage port 430 of the injection port 404 of the tissue expander 400.

In one embodiment, the needle guard base 418 of the needle guard 416 extends along a first axis A₁ and the membrane rim 425 of the moveable barrier membrane 422 extends along a second axis A₂ that is perpendicular to the first axis A₁ defined by the needle guard base 418. In one embodiment, as the moveable barrier membrane 422 moves and/or shifts between the first and second positions for opening and closing the inflation and drainage ports the moveable barrier membrane 422 including the membrane rim 425 travel up and down relative to the needle guard base 418 along the second axis A₂, which is perpendicular to the first axis A₁ of the needle guard base.

In one embodiment, the barrier rim 425 of the moveable barrier membrane 422 defines an outer diameter OD, of the moveable barrier membrane 422 that matches an inner diameter ID, defined by the needle guard rim 420, whereby an outer peripheral surface 427 of the barrier rim 425 engages an inner surface 421 of the needle guard rim 420 for guiding the movement of the moveable barrier membrane relative to the needle guard 416 between the first and position for inflating the shell (FIGS. 13A and 13B) and the second position (FIGS. 14B and 14C) for draining fluid that collects around the outside of the shell. In one embodiment, the needle guard 416 is designed to remain stationary within the injection port 404 and the barrier membrane 422 is designed to move up and down along the second axis A₂ for selectively opening and closing the respective inflation ports 428 and drainage port 430. In one embodiment, the barrier rim 425 slides over the inner surface 421 of the needle guard rim 420 when moving between the first and second positions.

Referring to FIGS. 15A and 15B, in one embodiment, a tissue expander 500 desirably includes an outer shell 502, and an injection port 504. The tissue expander 500 desirably includes a plurality of holes 508 that are formed in a top side of the outer shell 502. The series of holes 508 may be utilized for draining fluid that accumulates around the outside of the shell 502 and/or or infusing a medical solution through the holes 508 and around the outside of the shell 502. In one embodiment, the tissue expander 500 may include one or more drainage conduits and drains as disclosed herein. In one embodiment, the tissue expander 500 may include one or more infusion conduits as disclosed herein. In one embodiment, the tissue expander 500 may include a drainage conduit in communication with one or more of the holes 508 and an infusion conduit in communication with one or more of the holes 508.

Referring to FIGS. 16A and 16B, in one embodiment, a tissue expander 600 desirably includes an outer shell 602, and an injection port 604. The tissue expander 600 desirably includes a series of radially extending holes 608 that may be used for draining fluid that has accumulated around the outside of the shell 602 and/or infusing fluid from the holes to flow around the outside of the shell 602.

Referring to FIG. 17, in one embodiment, a tissue expander 700 preferably includes a shell 702 and an injection port 704 that is positioned in an opening of the shell 702. In one embodiment, the shell 702 preferably has a drainage opening 708 formed therein, and a drainage conduit 736 that extends between the drainage opening 708 and the injection port 704.

In one embodiment, the injection port 704 preferably includes an injection compartment 755. A first one-way check valve 758A is positioned between a first end 734 of the drainage conduit 736 and the injection compartment 755. Under vacuum, the first one-way check valve 758A opens for allowing fluid to be drawn into the injection compartment 755, such as by using a needle 742. Under pressure, the first one-way check valve 758A remains closed.

In one embodiment, the tissue expander 700 preferably includes a second one-way check valve 758B that enables inflation fluid (e.g., saline solution) to be introduced into the injection compartment 755 and flow past the second one-way check valve 758B into the interior of the outer shell 702 for inflating the tissue expander 700. The second one-way check valve 758B opens under pressure and remains closed under vacuum. Thus, the first one-way check valve 758A opens under vacuum and the second one-way check valve 758B open under pressure so that the first and second one-way check valves 758A and 758B are not open at the same time. In one embodiment, the same syringe/needle 742 may be used for delivering an inflation fluid into the injection compartment 755 on a forward stroke and evacuating drainage fluid from the injection compartment 755 on a reverse stroke.

In one embodiment, the injection port 704 of the tissue expander 700 desirably includes a third one-way check valve 758C that is located between the injection compartment 755 and an interior region of the shell 702. The third one-way check valve 758C is desirably opened under vacuum, but has a highly restricted aperture 765 so that under vacuum the third one-way check valve 758C will bleed some saline back into the injection compartment 755 for flushing the compartment and to also deflate the tissue expander 700.

Referring to FIG. 18, in one embodiment, a tissue expander 750 desirably includes an outer shell 802 and an injection port 804. The injection port 804 desirably includes a first injection chamber 855A that is in communication with first and second check valves 858A, 858B, and a second injection chamber 855B that is in communication with a third check valve 858C. A membrane 865 divides the first injection chamber 855A from the second injection chamber 855B. A distal end of an injection needle 852 may be passed through the membrane for accessing the second injection chamber 855B to inject a fluid into or remove a fluid from the second ejection chamber 855B.

In one embodiment, the first check valve 858A is coupled with a drainage conduit 836A in communication with a drainage opening 808A formed in the outer shell 802. The second check valve 858B is desirably in communication with an infusion conduit 836B that is coupled with an infusion opening 808B formed in the outer shell 802 of the tissue expander 800. The first one-way check valve 858A opens under vacuum in the first injection chamber 855A for draining fluid that has accumulated around the tissue expander through the drainage opening 808A and the drainage conduit 836A. The drained fluid may be removed from the first injection chamber 855A using a needle 842. The second one-way check valve 858B opens under pressure in the first injection compartment 855A for passing infusion fluid through the infusion conduit 836B to the infusion opening 808B. Thus, in one embodiment, the same syringe 842 may be used to deliver a fluid (e.g., an antibiotic solution) on a forward stroke via the infusion conduit 836B and to evacuate drainage fluid (e.g., seroma) via the drainage conduit 836A and the drainage opening 808A on a reverse stroke.

In one embodiment, the third valve 858C is located in the second injection chamber 855B. The third valve 858C may be used for inflating and deflating the outer shell 802 of the tissue expander 800. Under pressure, fluid in the second injection chamber 855B passes through the third valve 858C for inflating the outer shell 802. Under vacuum, fluid in the outer shell 802 is drawn through the third valve 858C into the second injection chamber 855B where it may be withdrawn using the needle 842.

Referring to FIG. 19, in one embodiment, tissue expander 900 includes an outer shell 902 with an injection port 904. The injection port desirably includes a first injection chamber 955A that is in communication with a drainage conduit 936A, and a second injection chamber 955B that is in communication with an infusion conduit 936B. In one embodiment, a first membrane 965A separates the first and second injection chambers 955A and 955B from one another. In one embodiment, the injection port 904 may include injection zone markers for locating and distinguishing between the first and second injection chambers 955A and 955B, as disclosed in commonly assigned U.S. Pat. No. 9,636,210 to Hristov et al., the disclosure of which is hereby incorporated by reference herein. The injection zone makers may be made of a material having ultrasonically detectable markers incorporated therein. In one embodiment, the markers may include a plurality of microcavities that are located relative to the first and second injection chambers of the injection port so that, when ultrasonically detected, such detection includes the locations of the first and second injection chambers.

The tissue expander 900 desirably includes a first check valve 958A that is coupled with a first end of the drainage conduit 936A. The drainage conduit 936A, in turn, is coupled with a drainage hole 908A provided in the outer shell 902. Under vacuum within the first injection chamber 955A, the first check valve 958A opens for allowing drainage fluid to be drawn through the drainage opening 908A, the drainage conduit 936A, and the first one-way check valve 958A, and into the first injection chamber 885A for being withdrawn from the first injection chamber using a needle 892.

The second check valve 958B is provided at a first end of the infusion conduit 936B. The infusion conduit 936B has a second end that is coupled with an infusion hole 908B formed in the outer shell 902. Under pressure within the second injection chamber 955B, the second one-way check valve 958B opens for allowing fluid injected into the second injection chamber 955B to pass by the second valve 908B, through the infusion conduit 936B and out of the infusion hole 908B for infusing the outer surface of the shell with a fluid.

In one embodiment, the third injection chamber 855C may be utilized for introducing fluid into the outer shell 852 for expanding the size of the tissue expander or withdrawing fluid from the outer shell 902 for reducing the size (i.e., deflating) the tissue expander 900. In one embodiment, the tissue expander 900 desirably includes a third valve 958C coupled with the third injection chamber 955C. A second membrane 965B separates the first and second injection chambers 955A, 955B from the third injection chamber 955C. A needle 942 may be passed through the first and second membranes for selectively accessing each of the injection chambers 955A-955C. Under pressure, the third check valve 908C opens for allowing solution, such as saline solution, to flow through the valve 908C and into outer shell 902 for inflating the tissue expander 900. Under vacuum, the third check valve 958C opens for drawing fluid from the outer shell 902 into the third injection chamber 955C for reducing the size of the tissue expander.

Referring to FIG. 20, in one embodiment, a tissue expander 1000 desirably includes an outer shell 1002 with a first injection port 1004A and a second injection port 1004B secured to the outer shell 1002. In one embodiment, the first injection port 1004A includes a first injection chamber 1055A in communication with a first check valve 1058A and a second check valve 1058B. In one embodiment, the tissue expander 1000 includes a first drainage conduit 1036A having a first end coupled with a drainage port in communication with the first check valve 1058A. The drainage conduit 1036A preferably includes a second end that is coupled with a drainage hole 1008A formed in the outer shell 1002 of the tissue expander 1000. In one embodiment, when a vacuum is drawn inside the first injection chamber 1055A, the first check valve 1058A opens for allowing any fluid that has accumulated around the exterior of the tissue expander 1000 to be drawn through the drainage hole 1008A, through the drainage conduit 1036A, past the open first check valve 1058A and into the first injection chamber 1055A for being withdrawn from the first injection chamber using a needle 1042.

In one embodiment, the second check valve 1058B is disposed between the first injection chamber 1055A and the first end of an infusion conduit 1036B. The infusion conduit 1036B has a second end connected with an infusion hole 1008B provided in the outer shell 1002 of the tissue expander 1000. In one embodiment, when pressure is provided inside the first injection chamber 1055A, the second check valve 1058B opens for allowing infusion fluid to flow by the second check valve 1058B, through the infusion conduit 1036B and out of the infusion hole 1008B for bathing the exterior of the outer shell 1002 with an infusion fluid.

In one embodiment, the second injection port 1004B of the tissue expander 1000 may be utilized for inflating and deflating the outer shell 1002 of the tissue expander 1000. In one embodiment, the second injection port 1004B desirably includes a second injection chamber 1055B and a third valve 1058C that opens under both pressure and vacuum. In one embodiment, when inflation fluid is injection via needle 1042 into the second injection chamber 1055B, the fluid under pressure opens the third check valve 1058C and the fluid passes into the interior region of the outer shell 1002 for inflating the tissue expander 1000. When a vacuum is drawn in the second injection chamber 1055B, the third check valve 1058C opens to allow the fluid inside the outer shell 1002 be drawn into the second injection chamber 1055B for being removed from the outer shell 1002 to deflate the tissue expander 1000.

FIG. 21 shows various systems and devices that may be used for creating a vacuum to drain fluid that has accumulated around the tissue expanders disclosed herein after the tissue expanders have been implanted inside patients. The devices may be coupled with the drainage conduits, injections chambers, and/or injection ports disclosed herein for drawing any fluid that has accumulated around the outsides of the outer shells of the respective tissue expanders. In one embodiment, a system for generating a vacuum preferably includes a compressible bulb 1115. In one embodiment, vacuum may be created using a flexible, compressible reservoir 1125 that draws a substantially constant vacuum to permit uniform removal of fluid from a surgical incision through a wound drain catheter, such as the surgical fluid evacuator disclosed in U.S. Pat. No. 4,429,693 to Blake et al., the disclosure of which is hereby incorporated by reference herein. In one embodiment, a system having a metered container 1035 may be used for drawing a vacuum to permit the uniform removal of fluid from a surgical site.

Referring to FIGS. 22A and 22B, in one embodiment, a drain 140′ preferably has an elongate, cylindrical core 166′ with four struts 168′ that project radially from the core 166′ along the longitudinal axis of the core. The radial struts 168′ are preferably of equal size and are spaced at equal angles relative to one another. Each of the outer ends of the radial struts 168′ have respective overhang portions 170′ which extend longitudinally throughout the length of the radial struts 168′. As shown in FIG. 6B, in one embodiment, the overhang portions 170′ are thin arcuate members that extend an equal distance on either side of their respective radial struts 168′. Thus, the overhand portions 170′ and the respective radial struts 168′ combine to form four T-shaped members. The overhang portions 170′ are sized to form a segmented circle at the periphery of the drain 140′, with small gaps between the adjacent overhang portions 170′. Each of these gaps forms a longitudinal groove 172′, parallel to the longitudinal axis of the core 166′, and extending throughout the length of the drain 140′. The core portion 166′, the radial struts 168′, and the overhand portions 170′ cooperate to form plural channels or lumens 174′ that extend along the length of the drain 140′. The longitudinal grooves 172′ permit fluid communication between the respective lumens 174′ and a wound. In one embodiment, the width of the longitudinal grooves 172′ is approximately 0.05-0.2 times the outside diameter of the drain 140′, which ensures adequate tissue contact in the drainage area while inhibiting tissue growth or entry of debris, such as clots, into the lumens 174′.

After breast reconstruction surgery, patients will have surgical drains placed to prevent blood and lymphatic fluid from building up under the skin, allowing for a quicker recovery. Some patients are sent home with drains that are implanted and connected to an external reservoir. Emptying these reservoirs can be traumatic as they have to measure and empty the reservoirs every morning. Patients cannot wait to have drains removed. Having a means to remove seroma fluid without the need for a drain being attached 24 hours a day is a great benefit to the patient.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, which is only limited by the scope of the claims that follow. For example, the present invention contemplates that any of the features shown in any of the embodiments described herein, or incorporated by reference herein, may be incorporated with any of the features shown in any of the other embodiments described herein, or incorporated by reference herein, and still fall within the scope of the present invention. 

What is claimed is:
 1. A tissue expander having an integrated drain comprising: a shell having an injection port opening and one or more drainage holes; an injection port disposed in said injection port opening of said shell, wherein said injection port forms a fluid-tight seal with said shell; said injection port including a needle guard having a needle guard base with a top surface; said injection port including a moveable barrier membrane overlying the top surface of said needle guard base, wherein said moveable barrier membrane is moveable between a first position for inflating and deflating said shell with a first fluid and a second position for draining a second fluid from outside said shell.
 2. The tissue expander as claimed in claim 1, wherein said needle guard includes a needle guard rim that extends upwardly from said needle guard base, and wherein said needle guard rim surrounds an outer perimeter of said moveable barrier membrane.
 3. The tissue expander as claimed in claim 2, further comprising: one or more inflation ports formed in said needle guard rim that are configured for directing the first fluid into said shell for inflating said shell and removing the first fluid from said shell for deflating said shell; at least one drainage port formed in said needle guard rim that is in fluid communication with said one or more drainage holes of said shell for drawing the second fluid from outside said shell via said one or more drainage holes.
 4. The tissue expander as claimed in claim 3, wherein said moveable barrier membrane has a membrane rim at an outer perimeter of said moveable barrier membrane.
 5. The tissue expander as claimed in claim 4, wherein when said moveable barrier membrane is in the first position said membrane rim closes said at least one drainage port and opens said one or more inflation ports, and wherein when said moveable barrier membrane is in the second position said membrane rim opens said at least one drainage port and closes said one or more inflation ports.
 6. The tissue expander as claimed in claim 5, wherein said needle guard base extends along a first axis and said needle guard rim extends along a second axis that is perpendicular to the first axis of said needle guard base, and wherein as said moveable barrier membrane moves between the first and second positions said moveable barrier membrane including said membrane rim travel up and down relative to said needle guard base along the second axis that is perpendicular to the first axis of said needle guard base.
 7. The tissue expander as claimed in claim 1, further comprising a drainage conduit having a first end in fluid communication with said at least one drainage port and a second end in fluid communication with said one or more drainage holes formed in said shell for draining the second fluid from outside said shell.
 8. The tissue expander as claimed in claim 1, further comprising: a magnet coupled with said moveable barrier membrane; a compressible spring coupled with said magnet, wherein said compressible spring is compressible for storing energy as said moveable barrier membrane moves from the first position to the second position.
 9. The tissue expander as claimed in claim 8, wherein said magnet has an upper end that is coupled with an underside of said moveable barrier membrane and a lower end that is coupled with said compressible spring.
 10. The tissue expander as claimed in claim 8, further comprising: a needle configured for being inserted into said injection port; a second magnet coupled with said needle, wherein when said needle is inserted into said injection port said second magnet repels said first magnet coupled with said moveable barrier for moving said moveable barrier from the first position to the second position.
 11. A tissue expander having an integrated drain comprising: a shell having an injection port opening and one or more drainage holes formed in said shell; an injection port disposed in said injection port opening; said injection port including a needle guard having a needle guard base and a needle guard rim that extends upwardly from said needle guard base; one or more inflation ports formed in said needle guard rim that are in fluid communication with an interior region of said shell; at least one drainage port formed in said needle guard rim that is in fluid communication with said one or more drainage holes formed in said shell; a moveable barrier membrane overlying a top surface of said needle guard base and being surrounded by said needle guard rim, wherein said moveable barrier membrane is moveable between a first position for closing said at least one drainage port and opening said one or more inflation ports and a second position for opening said at least one drainage port and openings said one or more inflation ports.
 12. The tissue expander as claimed in claim 11, wherein said moveable barrier membrane has an outer perimeter and a membrane rim located at the outer perimeter of said moveable barrier membrane.
 13. The tissue expander as claimed in claim 12, wherein said needle guard base extends along a first axis and said membrane rim of said moveable barrier membrane extends along a second axis that is perpendicular to the first axis of said needle guard base, and wherein as said moveable barrier membrane moves between the first and second positions said moveable barrier membrane including said membrane rim travel up and down relative to said needle guard base along the second axis that is perpendicular to the first axis of said needle guard base.
 14. The tissue expander as claimed in claim 13, wherein when said moveable barrier membrane is in the first position said membrane rim closes said at least one drainage port and opens said one or more inflation ports, and wherein when said moveable barrier membrane is in the second position said membrane rim opens said at least one drainage port and closes said one or more inflation ports.
 15. The tissue expander as claimed in claim 11, wherein said one or more inflation ports formed in said needle guard rim are configured for directing a first fluid into said shell for inflating said shell and removing the first fluid from said shell for deflating said shell, and wherein said at least one drainage port formed in said needle guard rim is in fluid communication with said one or more drainage holes formed in said shell for drawing a second fluid from outside said shell.
 16. The tissue expander as claimed in claim 11, further comprising: a magnet coupled with an underside of said moveable barrier membrane; a compressible spring coupled with said magnet, wherein said compressible spring is compressed for storing energy as said moveable barrier membrane moves from the first position to the second position.
 17. The tissue expander as claimed in claim 16, wherein said magnet has an upper end that is coupled with the underside of said moveable barrier membrane and a lower end that is coupled with said compressible spring.
 18. The tissue expander as claimed in claim 17, further comprising: a needle configured for being inserted into said injection port; a second magnet coupled with said needle, wherein when said needle is inserted into said injection port said second magnet repels said first magnet coupled with said moveable barrier for moving said moveable barrier from the first position to the second position.
 19. A tissue expander having an integrated drain comprising: a shell having an injection port opening and one or more drainage holes formed in said shell; an injection port disposed in said injection port opening; said injection port including a needle guard having a needle guard base that extends along a first axis and a needle guard rim that extends upwardly from said needle guard base; one or more inflation ports formed in said needle guard rim that are in fluid communication with an interior region of said shell for introducing a first fluid into said shell; at least one drainage port formed in said needle guard rim that is in fluid communication with said one or more drainage holes formed in said shell for draining a second fluid from outside said shell via said one or more drainage holes; a moveable barrier membrane overlying a top surface of said needle guard base and being surrounded by said needle guard rim, wherein said moveable barrier membrane is moveable along a second axis that is perpendicular to the first axis of said needle guard base between a first position for closing said at least one drainage port and opening said one or more inflation ports and a second position for opening said at least one drainage port and closing said one or more inflation ports; a magnet coupled with said moveable barrier membrane; and a compressible spring coupled with said magnet, wherein said magnet is disposed between said moveable barrier membrane and said compressible spring.
 20. The tissue expander as claimed in claim 19, further comprising: a needle configured for insertion into said injection port; a second magnet coupled with said needle, wherein when said needle is inserted into said injection port said second magnet repels said first magnet coupled with said moveable barrier membrane for moving said moveable barrier membrane from the first position to the second position.
 22. The tissue expander as claimed in claim 19, wherein said moveable barrier membrane has an outer perimeter and a membrane rim located at the outer perimeter of said moveable barrier membrane that extends along the second axis that is perpendicular to the first axis of said needle guard base, wherein when said moveable barrier membrane is in the first position said membrane rim closes said at least one drainage port and opens said one or more inflation ports, and wherein when said moveable barrier membrane is in the second position said membrane rim opens said at least one drainage port and closes said one or more inflation ports.
 23. The tissue expander as claimed in claim 19, further comprising a drainage conduit having a first end in fluid communication with said at least one drainage port and a second end in fluid communication with said one or more drainage holes formed in said shell for draining the second fluid from outside said shell via said one or more drainage holes. 